The 2zr-fe engine swap guide

[tmontague]

Originally Posted by ern-diz

Pardon my mechanical ignorance, but isn't VVT-i just V-Tech under a diff name? I've done a little research, but haven't been able to understand the difference. They're both just variable valve timing, right? Why is it that the Honda guys talk about 'V-Tech kicking in' and it seems VVT-i doesn't?

My understanding it vtec has valve lift where vvt-i is just variable timing. You essentially notice more "boost" w/ vtec but vvti is spread out more evenly through the rpm range.

The 2zr has dual vvti and I thought it also has valve lift capabilities which is likely why you feel the pick up after 4k.

Someone correct my post if incorrect

[MugenRep]

True VTEC (there are other ECO Vtecs now) has 3 lobe intake and/or exhaust cams that operate via a VTEC solenoid operated by raising oil pressure and the vehicles ECU to switch between a low lobe lift/duration initally and then a secondary lobe which has little more, and then to one that has very aggressive rates for life/duration. Modern I-VTEC also control timing on the intake cam via VTC in addition to the more aggresive intake/exhaust cams as revs rise.

If you ever go to a meet or show and see a loud high idle Honda, they're usually running a "VTEC KILLER" which is eliminiting the lost motion system which allows the lobes to change and just running the 3rd lobe which is hte most agressive. They dont' idle right under normal idle conditions because the cam profiles are too big.

[ern-diz]

Originally Posted by tmontague

My understanding it vtec has valve lift where vvt-i is just variable timing. You essentially notice more "boost" w/ vtec but vvti is spread out more evenly through the rpm range.

The 2zr has dual vvti and I thought it also has valve lift capabilities which is likely why you feel the pick up after 4k.

Someone correct my post if incorrect

Originally Posted by MugenRep

True VTEC (there are other ECO Vtecs now) has 3 lobe intake and/or exhaust cams that operate via a VTEC solenoid operated by raising oil pressure and the vehicles ECU to switch between a low lobe lift/duration initally and then a secondary lobe which has little more, and then to one that has very aggressive rates for life/duration. Modern I-VTEC also control timing on the intake cam via VTC in addition to the more aggresive intake/exhaust cams as revs rise.

If you ever go to a meet or show and see a loud high idle Honda, they're usually running a "VTEC KILLER" which is eliminiting the lost motion system which allows the lobes to change and just running the 3rd lobe which is hte most agressive. They dont' idle right under normal idle conditions because the cam profiles are too big.

Interesting, thanks.